Modern office with a dark blonde woman sitting at a desk and a mobile air conditioner in the background.
Air quality

air-Q tests: The effects of air conditioning in the office

Heat drives away concentration. What brings relief on hot days in the office? Clearly, air conditioning! But how does air circulation affect air quality? Do air conditioners pose a health risk? We checked and used the air-Q to analyze the effects of air conditioning in our own office.

Author:

Isabel Rüger & Undine Jaehne

Date:

8.7.2022

In principle, an air conditioner works in a similar way to a refrigerator: in order for the liquid refrigerant to absorb heat energy, the pressure of the refrigerant is reduced. This lowers the temperature in the cooling circuit. The refrigerant can thus absorb the higher temperature of the surrounding air and is carried away. Subsequently, the pressure of the refrigerant is increased, causing the temperature of the refrigerant to rise sharply. Now the heat energy can be transferred to the then relatively colder air. In a monoblock, the heated air is finally transported to the outside.

This process can lead to the formation of condensation. Finally, the air that comes into direct contact with the cooling circuit cools down very strongly. As a result, the water absorption capacity of the air reaches its limit. The relative humidity here is 100 % - i.e. the dew point has been reached.

This is how air conditioning affects the indoor air in the office

Air conditioning in the office not only reduces the temperature, but also as a side effect changes the humidity in the interior. Through the mechanism described above, moisture can be removed from the air. Since colder air absorbs and stores less water vapor, the absolute humidity of the air decreases. Depending on the individual design of the air conditioning system, the relative humidity can also change. How we perceive humidity depends very much on this value. When the air is colder, which can absorb less water vapor, and the absolute humidity is constant, the relative humidity increases.

Anyone who uses air conditioning in the office should make sure that the relative humidity does not fall below 40%. Above this value, the air is very dry and promotes colds. This is the reason why you often get sick in the car when the air conditioning is on. Because here the colder, very dry air comes into direct contact with the respiratory tract, while in a much larger room it can mix again with the rest of the room air.

Air conditioning as a risk in the office? These are the effects on health.

The use of air conditioning is naturally intended to reduce the temperature in the office. But poor maintenance or temperature differences that are set too high pose a health risk. Some employees also react sensitively to the artificially cool climate: freezing, tension due to excessive drafts and cold symptoms are the result. 

Circulatory problems & colds due to air conditioning in the office

Rapid changes between high and low temperatures stress the immune system and thus weaken the defense cells. If the difference between office and outside temperature is very large, there is even a risk of circulatory collapse. The abrupt drop in temperature also causes sweat to cool suddenly, and muscles can harden, resulting in tension. In addition, the dry air irritates the mucous membranes of the upper airways. This makes them more susceptible to pathogens, and many types of viruses enter the body more easily and can take hold better. Provide your mucous membranes in your air-conditioned office with sufficient fluids and drink especially much in cool offices. Since the skin also suffers from dry air and appears tense, you should apply cream to it regularly.

For an air conditioner to work properly, the windows must be closed. Therefore, no air exchange can take place and the viruses spread even more easily. The cardiovascular system is also put under great strain. Sleep disturbances, headaches or circulatory problems are the result.

Serious health effects of a poorly maintained air conditioner in the office

In addition to relatively harmless colds, serious infections can also be caused or aggravated by the operation of an air conditioning system in the office. The cause is usually poorly maintained air conditioning systems. If the filters and pipes are not cleaned or replaced regularly, they become an ideal breeding ground for germs. Germs, fungi and bacteria then quickly collect and multiply here. These pathogens then enter the human organism directly via the air flow.

High humidity, for example due to condensation, accelerates the growth of mold, the spores of which can trigger severe symptoms, especially in allergy sufferers. If your air conditioner gives off a musty smell, this is a clear sign of a contaminated and germ-laden system.

Watery eyes, a dry throat or frequent coughing and sneezing can also indicate that the air conditioning system is contaminated with germs.

Poorly maintained air conditioning systems can also be a source of infection for Legionnaires' disease. Legionella bacteria are not only found in large hot water systems in hospitals, large hotel buildings or swimming pools, but also in poorly maintained air conditioning systems. The small pathogens cause severe pneumonia with high fever.

As a preventive measure, only annual maintenance and cleaning of the air conditioner will help. You should definitely replace the filter regularly, so that germs do not settle here.

Open plan office with a desk at which a man and two women are looking into a laptop and look satisfied.
Together with a well-maintained air conditioning system, the air-Q air quality meter ensures good air quality in your office. Image source: portishead1 from Getty Images Signature/ canva.com

The best temperature setting for your office air conditioner

To avoid sweating outside and sniffling inside, the temperature difference between the office and the outside temperature should not be too great. Ideally, the difference should not be more than six degrees. After all, the smaller the difference between the indoor and outdoor temperature, the greater the risk of colds and circulatory problems when the temperature changes. This also protects the body, which is otherwise too stressed by the fluctuation. Ideal values are: 18 to 23 degrees room temperature and 35 to 65 percent humidity in the office. Most employees feel particularly comfortable at these values.

Of course, this general rule of thumb is often difficult to adhere to. If outside temperatures exceed 30 degrees, the recommended temperatures of 21 to 22 degrees in offices according to the German Federal Environmental Agency can hardly be achieved without intensively adjusted air conditioning.

air-Q Lab - Air quality analysis

In our office, we of course always record the air quality with the air-Q air measuring device. This way we can easily track a day using an air conditioner.

On the day of the test, the temperature rose sharply from 6 a.m. onwards as the first rays of sunlight penetrated the office until the maximum of 29 degrees was finally reached at 11 a.m.. From this point on, the mobile air conditioning was switched on, which caused the temperature to drop steadily to 25 degrees over the next few hours. From about 3:30 p.m., the air conditioning was switched off and the windows were opened, as it started to rain outside and became cooler. The absolute humidity, which had been constant until then, also dropped while the air conditioner was in use; however, it increased significantly after the air conditioner was turned off. However, this was also due to the fact that it was raining and the windows were opened to let in fresh air. The relative humidity never moved below 47 % during the test period, so there was no increased risk of colds here.

Diagram: air-Q air analyzer measures temperature and absolute humidity in the office when using an air conditioner.
Measurement curve for temperature and absolute humidity in the office
Diagram: air-Q air analyzer measures absolute and relative humidity in the office when using an air conditioner
Measuring curve for absolute and relative humidity in the office

Often air conditioners also have a fine dust filter or additional HEPA filter, which incidentally can even improve the air quality. The particulates-values in our room were low throughout the entire period, by the way, so no change was measured here. With the help of the air-Q and its many sensors, we could easily keep an eye on the changes in the air in our office and analyze the exact effects of the air conditioning and act accordingly.

For your health: monitor the air quality in your air-conditioned office

To ensure that the temperatures in your office cool down and that the air quality also remains good despite the air conditioning, you should monitor the air components. Air measuring devices such as the air-Q are ideal for this purpose. This is because the air-Q monitors many other components in addition to humidity and warns you when limit values are exceeded. In addition, the air meter detects the temperature, so that you always ensure an optimal climate at the workplace with an air-Q.

(Contributed image: Andrey_Popov/ shutterstock.com)

References
air-Q tests: The effects of air conditioning in the office
air-Q Air Quality Meter

Monitor air quality, all air components and environmental influences with the air-Q. For your health and performance.